Valve-seat reamer



6 z a 4 H. H 1| 2 v I 0 July 17. 1928.

- M. W. THAETE VALVE SEAT REAKER Filed April 19 1926 Patented July 17, 1928.

UNITED STATES PATENT. OFFICE.

MAXmILIAN W. THAETE, 01 DENVER, COLORADO, ASSIGNOR OF ONE-HALF TO MILLIE J. THAETE, OF DENVER, COLORADO.

VALVE-SEAT REAMER.

Application filed April 19, 1926. Serial No. 103,026.

My invention relates to reamers for reaming poppet-valve Seats, and more part1cularly to reamers which are adapted to be operated by either the unskilled person or the skilled mechanic with the same degree of success. i

It is a well established fact that in order to have the valve seat properly reamed, the valve seats must be of a uniform size. In order to attain such uniformity in size throughout, the use of reamers as now proposed it is required that the reamers be rotated the same number of revolutions in all of the valve seats utilizing the same or substantially the same pressure in each instance. Furthermore,reamers now in use are open to the objection in that they can only be retained in an upright or vertical position by the skill of the mechanic using such reamers and'if not retained in such position the valve seat will be cut in ragged or wavy manner. Also the reamers commonly used necessitate the changing of cutters for each changeof degree in the valve seat, and the cutters must be changed to ream the top of the block and the port. y

Accordingly, an object of my invention is to provide a reamer that will uniformly ream valve seats irrespective of the number of revolutions ofthe reamer or the pressure applied, thus enabling the use of such reamers by unskilled labor. A poppet valve by use will widen its seat, and it is an object of my invention to provide a reamer that will narrow the valve seat to its proper dimensions in one operation. In order to do this, it is necessary to cut the valve seat, the top of the block and the valve port simultaneously. Formerly, three operations were required.

Another object of my invention is to provide a reamer that will be retained in an upright position while in operation.

A still further object of my invention is to provide a reamer which will cut a narrow orwider seat Without necesitating the change in the cutters and will not out in a ragged or wavy manner.

()ther objects of my invention reside in the details of construction as will fully appear in the course of the description hereinafterset forth.

An embodiment of the invention has been illustrated in the accompanying drawings, in which like reference characters designate corresponding parts throughout the several views, and in which,

Figure 1, shows an elevation of my improved reamer;

Figure 2, a vertical section through the cutter and pilot stem, showing the reamer tool partly lifted out of the valve port and the respective angles comprising the valve seat cut by the tool, the stem of the tool being o'l a one piece construction;

ljigure 3, a view showing the cutter, shims, and nut in their respective relations but disassembled;

Figure a modification showing the pilot stem as being removable;

F gure 5, another modification, the stem having a sloping shoulder to engage the cutters:

Figure 6, shows the plug which is used inside the pilot stem of my reamer; and

Figure 7', a modification showing a diflerent manner of mounting the cutters.

Referring further to the drawings, the reamer consists of a shaft 5 having an integral nut 6 at the head thereof and an openlng M. The former is for the application of a wrench, the latter for the insertion of a bandle to rotate the tool. The shaft tapers down to a. pilot stem 7 at the other end thereof. The shank of theshaft carries screw threads 8 and spaced therefrom is an abut ting member or shoulder 9. Serrated cutters 10, 11, and 12 are firmly held on the shank between the shoulder and a nut 13 on the screw threads. These cutters carry teeth which project beyond the side or sides of the cutters and interlock with the teeth of the adacent cutter, thus forcing all of the cutters to rotate simultaneously with the tool. The teeth are arranged in staggered formation around the tool, which allows the tool to engage the work in numerous places thereby preventing the tool from chattering or reaming the valve seat in a. Wavy manner.

Shims 15 may be used to space the cutters if desired. The tool-illustrated is so constructedthat ifno shims are used, the

cutter 11 will not touch the Work, and only angle ofi'fi and the top of the: block 20 cut at an angle of 30, as graphically shown at 22, 23, and 21 in Figure 2. By changing cutters any angle or angles may be reamed. The purpose of cutting the port is to pro.- vide for the facile escape or entrance of or. air to or from the port 24, and also to. 'ayoid sharp corners, whlch might interhere with theoperati'on oil" thevalvcQ Moree oyer ,c i i-tter12 acts as a. guide for cutter 11. The function of cutter 10 isvto prevent cutter 1116510111 reaming. a. Wider seat than is desired, and also to assist in the facile pas sage of gases to, and from. the. port. Thus it is that irrespectiyeofthe amount of pressure, applied or the number 0t times thetool isrotated, theseat. cut by cutter 11 will be unifornrancl nolarger than desired, which, as stated, is regulated by the number of SlllllIlSr Gutter. 1 0 likewise prevents the mechanic trom cutting afpocket for the. valve seat, which would shut ofi' the passage of: gases. 01. air. Any oneormore of the cutters may be used by replacing each cutter with a spacer or sleeve. The cutters are removed by, uIlSQlQWiIlg he nut 1.3 and; pulling. the nut and cutters off over the pilot stem 7.

The pilot stem- 7 which is ot-hollow construction, haying tapered interior walls, is slit. longitudinally as at 1.6. to within a. short distance of the lower. end, and. is internally screw threaded as.- at 17: at. the lower extremity. A; plug. 18, is, carried in the holr low. portion of the, pilot, stem. The plug carriesa screw thre-aded, slottedhead. 19 to ngage theth eads 17; of the pilot, stem, and; to provide means for the application. of a.

screw driver.

The sides of the plug engage the interior Walls. ot the, pilot stem and; as the plug is.- pushed into thehQllOW. portionot thevalve stem, means of the screw-threaded head, the slit sides of the stemare distendedi The distentionoccurs at its greatest degree at the center. and gradually recedes toward; the. ends of the slits 'Ilhus Whenthe tool .with the sides of; the pilot stem distended, is pushed; down intov tlieyalye stemgu-ide 2'5, thestem frictionally engages the walls thereof, and prevents side: wise movement. oi the tool while the real ing is .be ing.done, since the distention occurs practically the, full length. of the stem. Mgreoyen the cutter 1;), acts as a guide and keeps the, cutter 11 in alinement so that the. valve seat will; be, properly reamed.

As stated, it hasbeen. necessary in the past to have skilled labor to place the reamer in position and to operate it for the valve seat must be reamed at the right place. In my device, since side play is reduced to a mini-.

mum, a novice may operate the reamer, in

shoulder being to. permit self-alinement off the cutters mounted: upon. the. shank.

In. Figure 2, it may be seen. that it is impossible. to make a pocket with my device. that wilt shut olii the flowof airto and: from the port 24 and further: the. seat 22' willfibe the same size, in every port reamed for. the. seat is the same size irrespective-of how. deep it isreamed. Angles. and; 2.31mainr. tain. theseat 22 at its, proper size. and! in, its relative position. I y

I peration. a sufiic ent number of; shims are placed between. the cutters of! my reamerto, allow the. cutter- 11 to; cut a. seat; of the. desired size. The cutter-sand shims are placed;

on the shank of the tool and the nut 13;

screwed home to firmlyholdthe cutters and shims between the nut. and. the shoulder 9.- T e p ug 18 is. then sc ewed ntothe hollow. stem until the desired distention of the latter takes, place. the valve stem guide and the reamer rosti ficl either. with a wrench ora handle. in-

serted in the hole 14. The cutters ream in,

three places simultaneously, to. the desired amount. The toohis lifted out Whenthe operation is complete. By means of my tool not only may an old seat be reamed. but; the top. of the block and. the. port. are cut at thesame. operation. I

In Figure, 7 modification of myjinven tion isshown. The cutters 10, ll and12, the. spacingmembers15, and the, nut 13 are all! mounted on a sleeve 26 whichhas a flare.27, at the upper end. In practice, thesleeve. with the members, mountedthereonis placed; on a shaft, either a tapering one as shown in Figure 5 or. one having an abutment shoulder as at 9, and held th'ereon by friction, by a nut screwed on the shaft, or any. other suitable means.

Having thus described my inventionwhat I, claim and desire to secure by LettersPatr. exit is 1. In a reamer, a shaft, a valve. seat-.cutter. mounted:- thereon, a pilot. cutter alsomounted on the shaft. and: adapted to out prior to the reaming. by. theyalye seat cutter to direct the first-mentioned cutter and to keep same The tool is then, pushed; into.

in alinement while the reamer is in operation, and means at the lower portion of the shaft below the cutters to hold the reamer vertical while reaming.

2. In. a reamer, a shaft, cutters on the shaft for reaming a valve seat and portions of the wall on either side thereof, in one operation, the relations of the cutters being such that the outer cutters determine the cutting width of the valve seat cutter, and 10 means for separating the cutters to vary said cutting width.

In testimony whereof, I hereunto afiix my signature.

MAXIMILIAN W. THAETE. 

